Abstract: The epididymis, an important organ of male reproduction, imparts sperm maturation acquiring motility and fertilizing potential and removal of defective sperm and providing good microenvironment. In addition the epididymis plays a significant role in the transport, concentration, protection, and storage of spermatozoa. The objective of the present study was to analyse the patho-physiological changes in epididymis, sperm morphology, count, maturation and transport under long-term hyperglycemic condition using Wistar Albino rats as diabetic (hyperglycemic) model. Twenty male Wistar albino rats (Rattus norvegicus) were used for this study (body weight 225– 250 g) The rats were randomly selected for the following groups i.e. group I – control (received 0.1M Citrate buffer) and group II – Diabetes (single injection of streptozotocin 60 mg/kg b.w. in 0.1M citrate buffer). At the end of 120 days animals were sacrificed by over dose of anesthesia (i.p), and followed by transcardial perfusion using 4 % paraformaldehyde in 0.1 M phosphate buffered saline. Epididymides were dissected out and after gross measurements were taken, processed for paraffin technique. Sections were stained using hematoxylin (Harris’s) and eosin and observed under light microscope and histomorphometry and stereological analyses were done. Spermatozoa were collected from caudal portion of epididymis to estimate sperm viability and motility, morphology and morphometry, cytoplasmic droplets and epididymal transit time. The present data revealed major damage in structure of epididymis and altered sperm quality and quantity under the influence of long-term diabetes. The alteration in epididymis might have influenced the sperm damage and poor sperm parameters leading to infertility. With the age limit to acquire diabetes is coming down rapidly and thus increasing the risk of infertility in younger generation. Consequently, more number of basic and clinical researches should be focused on the prevention and cure of diabetes.